Pires was born on August 23, 1963 in Rio de Janeiro. She is the daughter of producer Elza Pires and actor Ant?nio Carlos Pires. She has a sister named Linda Pires, a therapist.　　Glória made her debut as an actress at the age of 5, on the telenovela A Pequena ?rf?, broadcast on the now defunct TV Excelsior. She initially participated only in the show's opening sequence, but director Dionísio Azevedo would later cast her to play a minor character. On her first day of shooting, however, she experienced a nasal hemorrhage and was removed from the telenovela. Later, when the lead actress Patrícia Ayres dropped out due to contractual reasons, Glória had a second chance by dubbing Ayres' voice at such a young age.　　In 1980, after she left the hospital, Glória decided to change her appearance, cutting and lightening her hair. Her next telenovelas were ?gua Viva and As Três Marias, an adaptation of Clarice Lispector's novel of the same name. She made a deal with Globo so that she could act in her first feature film after the end of this telenovela.　　In 1990, Glória starred in Mico Preto, followed by O Dono do Mundo.She received the Troféu Imprensa Award for Best Actress for her performance in the telenovela.　　In 2013, she starred the movie Reaching for the Moon along with Miranda Otto, the film follows the real love story between the American poet Elizabeth Bishop and Brazilian architect Lota de Macedo Soares.